Laboratory equipment



Oct. 24, 1961 E. G. WEICHSELBAUM 3,005,564

LABORATORY EQUIPMENT Filed Oct. 12, 1959 I. p. I. I. I

0 INVENTOR. f 5 1/ [75. 6 W/VG WF/Cl/JZZ 14 M ATTY.

State This invention relates in general to certain new and usefulimprovements in laboratory equipment and, more particularly, to a newand unique closure for laboratory glassware, such as test tubes,spectrophotometer tubes, nephelometer tubes, and the like.

In analytical laboratories, such as those which are found in hospitals,medical clinics, industrial plants, and the like, various types oflaboratory glassware are routinely used for analytical procedures. Forinstance, several different types of glass tubes, generally resemblingtest tubes in shape, are used in spectrophotometers for containingliquid samples which are being subjected to spectrophotometric analysis.In other types of analytical procedures where the end result is obtainedby color comparison, tubes of somewhat similar shape and design areemployed in colorimeters, nephelometers, and similar apparatus. In fact,there is quite a wide range and variety of this type of laboratoryglassware which is currently in use in scientific laboratories of allsorts.

One of the problems which is encountered in the use of such laboratoryglassware relates to the stoppers or closures therefor. At the presenttime, it is conventional practice to use a solid rubber stopper which isforced down into the open or mouth end of the glass tube or vessel. Ifthe stopper is not forced into place firmly it often slips outunauthorizedly, resulting in spillage or contamination of the sample. Onthe other hand, when the stopper is pressed too tightly in place, theupper end of the tube is occasionally broken. In addition to this, theupper portion of the glassware adjacent to the stoppered end very oftenwill strike against some hard object, such as a table top or other pieceof glassware, and the atent O impact will crack or break the upper endof the tube,

particularly if it is under some degree of tension as a result ofstoppering.

Another and closely related problem in connection with closures orstoppers for laboratory glassware results from the wide variety ofdifferent sizes employed for such glassware. Since solid rubber stoppersmust fit snugly and yet cannot be inserted with excessive force, it isnecessary to have a different sized stopper for each different sizedtube or vessel, with the result that the average laboratory must containquite a stock of stoppers in a large range of sizes. It is not onlycostly to maintain such a stock of stoppers, but it also occasionsconsiderable loss of valuable time, inconvenience and annoyance to sortthrough the various sized stoppers and pick out the right size each timeone is required. Similarly, it is also timeconsuming, after the stoppershave been used and washed, to sort them out and again return them, eachto its proper storage bin, storage compartment, or container.

It is, therefore, the primary object of the present invention to providea closure or stopper for laboratory glassware which is uniquelyconstructed so as to fit snugly and securely within the open or mouthend of a piece of laboratory glassware and form a tight, secure closuretherefor without exerting undue bursting pressure or rim pressure uponthe upper end of the glassware.

It is another object of the present invent-ion to provide a closure orstopper of the type stated which will readily accommodate itself tovariations of internal diametral size of the mouth of the piece ofglassware into which it is inserted.

It is also an object of the present invention to provide a closure orstopper of the type stated which will protect the upper end of the pieceof glassware into which it is inserted and prevent breakage thereof dueto accidental impact with other objects.

With the above and other objects in view, my invention resides in thenovel features of form, construction, arrangement, and combination ofparts presently described and pointed out in the claims. I

In the accompanying drawing (one sheet) FIG. 1 is a perspective view ofa stopper or closure constructed in accordance with and embodying thepresent invention;

FIG. 2 is a vertical sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a perspective view of a laboratory tube stoppered with aclosure constructed in accordance with the present invention;

FIG. 4 is a fragmentary sectional view taken along line 4- 4 of FIG. 3;

FIG. 5 is a transverse sectional view taken along line 5-5 of FIG. 4;

FIG. 6 is a perspective view of a difierent type of laboratory glasstube stoppered with a closure constructed in accordance with the presentinvention; and

FIG. 7 is a fragmentary sectional view taken along line 7-7 of FIG. 6.

Referring now in more detail and by reference characters to the drawing,which illustrates a preferred embodiment of the present invention, Adesignates a closure or stopper which is molded as an integral orone-piece unit from a suitable rubber-like synthetic resin or so-calledplastic material such as polyethylene and comprises a central somewhatcup-shaped element 1 having a flat bottom member 2 and a somewhatfrusto-conical .side wall 3 extending upwardly therefrom at an outwardlydiverging angle of taper t. It has been found in connection with thepresent invention that this angle of taper should not be less than 5 normore than 10 for reasons which will be presently more fully discussed.At its upper'end, the side wall 3 merges integrally into a relativelyheavy annular collar 4 which is provided around its outer face 5 with arough pattern, such as, forexample, a vertical series of serrationswhich serve to facilitate gripping the stopper A with the fingers. Theupper margin of the collar 4 is preferably, though not necessarily,beveled as at 6 so that the grip-forming serrations or pattern on theannular face 5 will not intersect the flat top face 7 of the stopper A.It will also be noted by reference to FIG. 2 that the interior annularface 8 of the collar 4 is cylindrical and merges with the interior faceof the side wall 3 along a circular line ofdemarcation 9 which is.coplanar with the downwardly presented under face 10 of the collar 4.

Formed integrally with, and extending downwardly from, the under face'10 of the collar 4 is a skirt member 11 which terminates at its lowerend in a transverse margin 12 which is coplanar with the under face ofthe bottom member 2. For a substantial distance upwardly from the bottommargin 12, the skirt member 11 is substantially cylindrical and thentapers inwardly. at an angle of taper which is several degrees greaterthan the angle of taper t, thus forming an inwardly tapering integralband 13 which, in vertical height, is approximately one-fifth the heightof the cylindrical portion of the skirt member 1 1.

In use, the stopper A can be conveniently and easily fitted into theopen or month end of a glass tube B and the tapered central cup-shapedelement 1 will seat itself snugly and conformably into the interiorthereof. As a result of the hollow interior of the cup-like element 1and 3 the angle of taper t, it is possible, with a single size ofstopper A, to accommodate a fairly wide range of different glass tubes.The angle of taper t within the range above specified is substantiallygreater than the conventional angle of taper employed on solid rubberstoppers and corks. Consequently, with solid rubber stoppers, it isnecessary to utilize something of the order of thirty to forty differentsizes in order to accommodate various types of laboratory glasswarecommonly in use. With the stopper A of the present invention, it ispossible to accommodate this same range with only seven differentstopper sizes. Moreover, the angle of the taper t and the fact that thecup-like element 1 is hollow makes it possible to achieve a much moresecure effective closure within' the mouth end of the glass tube B orother simi lar piece oflaboratory glassware without imposing excessivebursting or so-called rim pressure on the glass. Finallyythe skirtelement 11 will envelope the upper portion of the glass tube B andprotect it against chipping and breaking as a result of accidentalimpact or shock.

Certain types of glass tubes which require an unusually tight seal canbe pushed all the way up into the doubly tapered recess between theupper portion of the side wall 3 and the annular band portion 13 of theskirt member 11' substantially as shown in FIG. 4.

The stopper A may also be used equally well with glass tubes'such as thetube B shown in FIG. 6, which has an: upwardly and outwardly flaredfire-polished rim 14 which stretches the skirt member 11 and seatsitself tightly therein somewhat in the manner shown in FIG. 7.

It should be understood that changes and modifications' in' the 'form,construction, arrangement, and combination of the several parts of thelaboratory equipment maybe made and substituted for those herein shownand described without departing from the nature and principle of'myinvention.

Having thus described'my invention, what I claim and desire to secure byLetters Patent is:

1. A. closure for laboratoryglassware such as test-tubes, sample tubes;and the like, which have'substantially cylindrical neckszterrninating ina substantially circular mouth; said closure comprising ataperedplug-like element adapted' for insertion into said mouth andbeing integrally provided: at-its larger end with a diametrally enlargedcollar', the'angle of taper of the plug-like element being from to110?with-respect to: the lbngitudinal aXis thereof, said collarhavingazdepending skirt which encircles the plug like element and is'provided with an inwardly presented'cylindricalface disposedin annularlyspaced relation to theplug, said skirt being connected at its upper endtol'thecollar' by an axiallyinwardly tapering band, said band having avertical height substantially shorterthan' the height of said skirt.

2.1 A closurefor laboratory glassware such as test-tubes, sample tubes,and the like, which have substantially cylindrical necks terminatingin asubstantially circular mouth; .saidi..closure comprising ataperedplug-like element adapted for insertion into said: mouth and beingintegrally provided at: its larger end with a diametrally enlargedcollar having adepending-integral skirt which encircles-the plug-like:element and is. provided with an inwardlypresentedcylindrical facedisposed in annularly spacedirelationsto the plug, the lower margin ofthe skirt being substantially. coplanarwith the lower margin of thep1ug,=said:skirt being connected at its upper end to the collarby"an:axially inwardlytapering band, said band having :av'erticalheightsubstantially. shorter than the heightiof saidskirt.

3. A closure for laboratory glassware such as test-tubes, sample tubes,and the like, which have substantially cylindrical necks terminating ina substantially circular mouth; said closure comprising a tapered hollowpluglike element adapted for insertion into said mouth and beingintegrally provided at its larger end with a diametrally enlargedcollar, the angle of taper of the pluglike element being from 5 to 10with respect to the longitudinal axis thereof, said collar having adepending skirt which encircles the plug-like element and is providedwith an inwardly presented cylindrical face disposed in annularly,spaced relation to the plug, said skirt furthermore being connected atits upper end to the collar by an axially short inwardly taperedsection, said tapered section having a vertical height substantiallyshorter than the height of the cylindrical face of said collar.

4. A closure for laboratory glassware such as test-tubes, sample tubes,and the like, which have substantially cylindrical necks terminating ina substantially circular mouth; said closure comprising a tapered hollowplug-like element having'a fiat bottom wall adapted for insertion intosaid mouth and being integrally provided at its larger end with adiametrally enlarged collar, the angle of taper of the plug-like elementbeing from 5 to 10 with respect to the longitudinal axis thereof, saidcollar having a depending skirt which encircles the plug-like element inannularly spaced relation thereto, said skirt beingconnected at itsupper end to the collar by an axially inwardly tapering band, said bandhaving a vertical height substantially shorter than the height of saidskirt.

5. A closure for laboratory glassware such as test-tubes, sample tubes,and the like, which have substantially cylindrical necks terminating ina substantially circular mouth; said closure comprising a taperedplug-like element adapted for insertion into said mouth and beingintegrally pro vided at its larger end with a diametrally enlargedcoilar having a depending skirt which encircles the plug-like elementand is provided with an inwardly presented cylindrical face disposed inannularly spaced relation to the plug and is connected to the undersideof the collar by an inwardly tapering section which is substantiallyshorter than the axial length with respect to the axial length of theremainder of the skirt.

6. A closure for laboratory glassware such'as test-tubes, sample tubes,and the like, which have substantially cylindrical necks terminating ina substantially circular'mouth; said closure comprising a plug-likeelement adapted for insertion into said mouth, said plug-like elementhaving a downwardly diverging angle of taper of 5 to 10 with respecttothe longitudinal axis thereof, said element further being integrallyprovided with'a diametrally enlarged collar at its larger end, saidcollar having a depending shift which encircles the plug-like elementand is provided with an inwardly presented cylindrical'face disposed inannularly spaced relation to the plug, said skirt being connected at itsupper end to the collar by an axially inwardly tapering band, said bandhaving a vertical height substantially shorter than the height of saidskirt.

References Cited in the file of this patent OTHER REFERENCES 2,487,400Tupper Nov. 8; 1949 2,638,261 Poole May 12, 1953 2,717,728 Gray Sept.13, 1955 FOREIGN Y PATENTS 1,023,521 France Mar. 19, 1953

